The cause of the cam failure may be in the oil itself.  Our government in all of its infinite wisdom has decided the the zinc and phosphorus in the older oil is a pollutant and in the last several years taken it out.  This does not affect roller tappet motors but will reek havoc on flat tappet cams.

Here is a snippet from a website on the issue:

 "The EPA has put stricter emission requirements on new cars that influenced manufacturers to remove ZDDP from motor oils. If you have an older car that was specified to use SF (1988) or earlier motor oil, its design requires ZDDP. Your older performance car could be damaged with the use of modern SM oils prevalent today. Cars equipped with flat tappet cams need ZDDP because of the high-pressure points. Newer cars have roller rockers and ZDDP is not needed in those applications"

Here is the website from where the quote came from.  Although they are trying to sell a product,  there is much information about this.

http://www.zddplus.com/

This from Wikipedia:

"The main use of ZDDP is in anti-wear additives to lubricants such as greases, gear oils, and motor oils, which often contain less than 1% of this additive. It has been reported that zinc and phosphorus emissions may damage catalytic converters and standard formulations of lubricating oils for gasoline engines now have reduced amounts of the additive, though diesel engine oils remain at higher levels.[3]. Crankcase oils with reduced ZDDP have been cited as causing damage to, or failure of, classic/collector car flat tappet camshafts and lifters which undergo very high boundary layer pressures and/or shear forces at their contact faces, and in other regions such as big-end/main bearings, and piston rings and pins. Roller camshafts are more commonly used to reduce camshaft lobe friction in modern engines. Some racing oils such as Valvoline ZR-1, are available in the retail market with the necessary amount of ZDDP for engines using increased valve spring pressures. See "external links" in this article. The same ZDDP compounds serve also as corrosion inhibitors and antioxidants."

Seems like your cam failed very quickly and this may not be it, but it is something you may look into.

Hope this helps out and you figure out your problem

sandfantom